Self guiding force applicator

ABSTRACT

A self guiding force applicator includes a tubular mandrel to deliver fluid to drilling means. A piston carried by the mandrel moves in a cylinder to which fluid is supplied to force mandrel or cylinder in or out. The mandrel and cylinder are connected by spline means to prevent relative rotation while allowing relative axial motion. Releasable anchor means anchors either cylinder or mandrel to wall of bore hole dependent upon whether mandrel or cylinder is to be moved. The mandrel anchor means is disposed at the outer end of the force applicator to serve as a guide means when in the released position during drilling. Also at the outer end of the mandrel is a manifold for connecting conduits and passages in the mandrel to an outer end of the force applicator. The hose line is wound on an out-of-hole winch mounted on a trailer cart. Launching means for the force applicator and drilling means, together with supply and control means for the anchor means, piston and cylinder means, and the drilling means, is also mounted on the car.

United States Patent Kellner et al.

[ 1 SELF GUIDING FORCE APPLICATOR [75] Inventors: Jackson M. Kellner;George Abraitys Alther, both of Midland, Tex.

[73] Assigneei Smith International, Inc., Midland,

Mich.

221 Filed: Apr. 16, 1973 21 Appl. No.2 351,628

Related US. Application Data [63] Continuation of Ser. No. 189,845, Oct.18, 1971,

abandoned.

[52] US. Cl 175/94, 175/99, 175/203, 175/230 [51] Int. Cl. E21b 3/12,E2lb 19/08, E210 9/00 [58] Field of Search 175/94, 97, 99, 98, 230,175/203, 122, 62, 220, 53; 51/727; 299/31; 254/1346 [56] ReferencesCited UNITED STATES PATENTS 556,718 3/1896 Semmer 175/94 2,500,7853/1950 Arutunoff 175/203 X 2,712,920 7/1955 Cullen et a1. 175/992.946.578 7/1960 De Smaele 175/62 X 3,180,437 4/1965 Kellner et al.175/230 3.354.969 11/1967 Ebeling.....- 175/94 Mar. 19, 1974 3,376,9424/1968 Van Winkle 175/99 X 3,399,738 9/1968 l-laspert 175/53 3,604,7549/1971 Kampf-Emden et al. 299/31 X 3,643,999 2/l972 Kampf-Emden et a1299/31 Primary ExaminerDavid H. Brown cylinder or mandrel to wall ofbore hole dependent upon whether mandrel or cylinder is to be moved. The

' mandrel anchor means is disposed at the outer end of the forceapplicator to serve as a guide means when in the released positionduring drilling. Also atthe outer end of the mandrelis a manifold forconnectingconduits and passages in the mandrel to an outer end of theforce applicator. The hose line is wound on an out-of-hole winch mountedon a trailer cart. Launch- ,ing means for the force applicator anddrilling means,

together with supply and control means for the anchor means, piston andcylinder means, and the drilling means, is also mounted on the car.

18 Claims, 20 Drawing Figures PATENTEDMAR 19 I974 SHEET 1 U 7 s AQ/fibli a R \W a PATENTEUHAR 19 mm 87971589 sum u 0F 7 I NM If %WW ISELF GUIDING FORCE APPLICATOR CROSS REFERENCE TO RELATED APPLICATIONThis application is a continuation of prior copending application Ser.No. 189,845, filed Oct. 18, 1971, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to earth boring and more particularly to a force applicator foraxially loading a drill bit, especially an in-hole motor driven drillbit used in boring horizontal vent holes in mining for coal.

2. Description of the Prior Art Coal bed vent holes have been drilledwith auger bits. After the hole exceeds several hundred feet in lengthdifficulty is experienced in maintaining directional control. The use ofan in-hole drilling machine has been suggested to eliminate the need fortransmitting torque the length of the drill stem. However, it was stillnecessary to use the drill stem to transmit axial forces to load thebit. In drilling oil wells it is known to provide inhole bit loadingmeans, as shown for example in U.S. Pat. Nos. 3,088,532 issued May 7,1963 on the application of J. M. Kellner and 3,298,449 issued Jan. 17,1967 on the application of W. R. Bachman et al. Automatic valve meansfor such apparatus is shown in U.S. Pat. No. 3,105,561 issued Oct. 1,1963 on the application of J. M. Kellner.

In the application of said Jackson M. Kellner filed contemporaneouslyherewith, Ser. No. 189,844, filed Oct. 18, 1971, now abandoned, and thecopending continuation thereof application Ser. No. 351,629 filed Apr.16, both entitled FORCE APPLICATOR, an inhole force applicator isdisclosed in combination with an in-hole motor driven bit for effectingbetter direction control in the drilling of horizontal earth bores. Thetubular mandrel for supplying fluid to the in-hole motor driven bit isprovided with a piston connected to the mandrel which moves in acylinder that is connected to the mandrel by spline means. Fluid isapplied to the cylinder to move the piston or cylinder in or out asdesired. Releasable anchor means are connected to the cylinder andmandrel to anchor one or the other to the bore wall when the other orone is to be forced in or out. The mandrel anchor means is disposedbetween the in-hole motor driven bit and the piston and cylinder means.A guide means in the form of a centralizer or stabilizer is connected tothe mandrel axially outward from the piston and cylinder means.

According to one form of the apparatus disclosed in said contemporaneousKellner application a plurality of flexible fluid conduits supply fluidto the two sides of the piston and cylinder means and to the tworeleasable anchor means and to the in-hole motor driven bit. The guidemeans body serves also as a manifold for connecting the flexibleconduits to the fluid conduits of the force applicator. The plurality ofconduits extend out to the open end of the bore hole where they arewound on motor driven reels or winches. Out-of-hole hydraulic controlmeans is provided for manually or automatically supplying fluid to thedesired in-hole means for effecting inward or outward travel of themandrel or cylinder.

SUMMARY OF THE INVENTION The present invention is upon improvement upnthe prior conceived invention disclosed in the aforesaid contemporaneousapplication of Jackson M. Kellner.

According to the present invention there is provided a force applicatorsimilar to that of the above described Kellner force applicator butwherein the mandrel anchor is disposed axially outward of the piston andcylinder means where, when in the unset, i.e. disengaged or retracted,condition it will function as a guide means, thereby eliminating theneed for separate guide means at this position along the mandrel andshortening the overall length of the apparatus for any given stroke. Inaddition, such positioning of the mandrel anchor means makes itunnecessary to transmit fluid for such anchor means through the rest ofthe force applicator. This also simplifies the. construction of the hoseconnection manifold which serves also as means to connect the mandrel tothe barrel of the mandrel anchor means. Further in accordance with theinvention the flexible conduits supplying fluid to the force applicatormay be bondedinto a single multiple fluid passage flexible conduit.Improved reeling means and hydraulic control means are provided.

BRIEF DESCRIPTION OF THE DRAWINGS For a detailed description of .apreferred embodiment of the invention and modifications thereofreference will now be made to the accompanying drawings (FIGS. 3 thru 16are substantially full size and to scale for an exemplary tool) wherein:

FIG. 1 is a semi-schematic view' showing a vertical section through ahorizontal earth bore with apparatus according to the invention disposedtherein shown in elevation and in section;

FIG. 2 is a schematic view illustrating an inhole rotary drillingmachine with which the subject invention may be used; 1

FIGS. 3, 4, 7, I0 and 11 together form an axial section through a forceapplicator according to a preferred embodiment of the invention;

FIGS. 5, 6, 8, 9, 12, 113, 14, 15, 16 are transverse sections takenthrough the force applicator shown in the preceding drawings, suchsections being taken on the planes indicated in said preceding drawings;

FIG. 17 is a perspective view showing out-of-hole apparatus used inconjunction with the in-hole apparatus shown in the preceding drawings,said in-hole apparatus also being shown being launched into the hole;

FIG. 17A is a sectional view through the hose 87; and

.FIGS. 18 and 119 are schematic views showing hydraulic systems usefulin the out-of-hole apparatus.

As is apparent from the sectioning of the drawings, all parts are madeof steel unless otherwise indicated or stated.

DESCRIPTION OF THE PREFERRED EMBODIMENT In this patent specification,unless the context indicates otherwise, the term inward is used todenote the axial direction toward the closed end of the bore hole andthe term outward is used to denote the axial direction away from theclosed end of the hole.

Since this application discloses improvements on the constructiondisclosed in the aforesaid contemporaneous application of Jackson M.Kellner, the disclosure thereof is incorporated herein by reference forthe disclosure and description of various details of the presentconstruction which are the same as those of the construction disclosedin said contemporaneous Kellner application thereby avoiding repetition.

Referring now to FIG. 1, there is shown an earth bore 51. The term earthis here and in the claims used in a broad sense to cover all materialsof which the planet Earth is formed; it will be understood thatfrequently the earth will be coal. At the inner end of the earth bore isa drill bit 53 connected to the rotary drilling machine 57. Thenon-rotating part 59 of the drilling machine is connected to mandrel sub61. The sub 61 is in turn connected to mandrel 63 of force applicator64.

The mandrel, which is made up of a number of tubular sections, includesa spline section 65 which carries an externally fluted sleeve 67. Sleeve67 travels axially applicator is used to apply force to the drillingmachine 57. The anchor means in turn is connected to cylinder 77. Themandrel 63 continues on from the spline section 65 thereof throughcylinder anchor means 73 into cylinder 77 where its piston rod section79 is provided with a piston 81. Piston 81 reciprocates in cylinder 77and together the piston and cylinder form piston and cylinder means 83.I

The piston rod section of the mandrel extends outwardly beyond cylinder77 and connects to mandrel anchor and guide means 85. The anchor andguide means in turn connects to flexible hose line 87 which extends outthe open or outer end of the earth bore. A guide funnel 91 is disposedin the open end of the earth bore.

The hose line 87 is either a bundle of five separate hoses or is asingle hose that includes five fluid passageways. The hose line 87connects intoa manifold provided by the body of anchor and guide means85. The fluid from hose 87 is used to supply pressure fluid to the twoanchor means and the two sides of the piston and cylinder means and tothe rotary drilling machine,

being conducted via the manifold and the mandrel and known as aDyna-Drill. Apparatus of this type is shown in various publications. SeeUS. Pat. Nos. 2,898,087 and 3,112,801, and Dyna-drill Handbook publishedI970 by Dynadrill Div. of Smith Autl., Inc. Such a rtary drillingmachine is shown schematically in FIG. 2, which is based on theillustration at the right on page 1,870 of the l970-7l edition of theComposite Catalogue of Oil Field Equipment and Service. As theredescribed, the drilling machine 57 includes a motor 101 which isessentially a three-stage Moyno Pump run in reverse and comprising aboutone-half of the total 25 foot length of the tool. The motor consists ofan obround-shaped spiral passage 103 containing a solid steel rotor 105which moves eccentrically. Shaped in a regular-recurring wave form, thisrotor is free to move at the outer end 107, while the inner end 109 isattached to one end of a connecting rod 111. The other end of theconnecting rod is attached to tubular drive shaft 113. Thrust bearings115, 117 on the drive shaft prevent it from moving axially insidehousing extension 119. When water is pumped under pressure into housingconnection 121 at the outer end of the tool, the pressure closes springloaded slide dump valve 123, closing port 125. The water is thusdirected down the annulus 127 between the rotor 105 and the rubber linedspiral passageway 103. In order for flow to occur, the rotor isdisplaced and turned by the pressure of the fluid column, thus rotatingthe connecting rod l11,the tubular drive shaft 113 and the bit sub 129.The latter is connected to the inner end of the drive shaft where itextends out beyond housing extension 119. The water, or other fluid,leaves the annulus 127 by entering port-131 in the tubular drive shaft.The water then passes through the drive shaft, bit sub, and diamond bit53, and leaves bit 53 via passages 133, where it enters the bore hole.The water leaving the drill bit passes back to, the open end of the holeoutside the drilling machine, the force applicator, and the hoseconnected thereto, carrying away the detritus and cooling the bit. Itwill be seen that although the drive shaft 113 rotates relative to thetool housing 135, inward force applied axially to the housing throughconnection 121 is trans ferred to the drive shaft 1 13 through thethrust bearings 117 and thence to the bit 53. Likewise, .outwardlydirected force applied to housing 135 is transferred to the drive shaftthrough thrust bearing and thence to the bit.

Referring now to FIGS. 3 et seq., there are shown the details of a forceapplicator embodying the invention. Beginning with FIGS. 36 there isshown in detail the spline means 71 and cylinder-anchor means 73 shownschematically in FIG. 1. At the right hand side of FIG.

3 is shown the sub 61 (see also FIG. 1) for making con nection with thedrilling machine 57. The sub 61 is screwed onto pin 516. Pin 516is'welded on to the inner of a pipe 518. The outer end of pipe 518 iswelded to threaded box 520 (FIG. 4). Together, the pin 516, tube 518,and box 520 form the spline section 65 (FIG. 1) of the mandrel of theforce applicator.

Externally fluted sleeve 67 is pressed or shrunk onto pipe 518. Disposedaround spline section 65 of the mandrel is tube 69, which, as best shownin FIG. 5, is internally fluted correlative to fluted sleeve 67. Thereis thus provided spline means 71 which allows relative axial motion ofthe mandrel and tube while preventing relative motion therebetween. Theflutes on the sleeve 67 leave axially extending ribs 519 therebetweenwhich fit between the ribs 521 of fluted tube 69. The ribs 519 areprovided at their outer peripheries with channels 523 to permit solidmaterials to be flushed more easily out of the spline means 71. I

To the inner end of tube-69 (FIG. 3) is screwed a coupling 522 which inturn is screwed to guard cup 526. The guard cup 524 and sub 61 cooperateto provide stop means limiting relative axial travel of the mandrel andtube, end 525 of the guard cup being engageable with end 62 of sub 61.

Within coupling 522 is pressed or shrink fitted a seal ring 526 havingan annular rubber seal 528 bonded to the inner periphery thereof. Thespline section 65 of the mandrel of the force applicator extends axiallythrough seal ring 562 in sealing engagement with seal 528.

As shown in FIG. 4, the box 520 is screwed onto pin 530 which forms theinner end of the piston rod section 79 (see also FIG. 1) of the mandrelof the force applicator. Section 79 further includes pipe 532 to whichpin 530 is welded. Pipe 532 extends axially slidably through and insealing engagement within annular rubber seal S34 bonded to the interiorof the combined barrel head and cylinder-head formed by seal ring 536.The latter is press or shrink fitted inside coupling 538.

A barrel 540 is screwed at one'end to coupling 538 and at the other endto spline tube 69. There is thus formed a chamber 543 between themandrel and the barrel and spline tube, the chember being sealed at itsends by seals 534 and 528 of seal rings or barrel heads 536 and 526.Pressure fluid may be conducted into and out of the chamber 543 throughmandrel port 541, the latter being connected to conduit 546 whichextends outwardly to the outer end of the force applicator where itconnects to a pressure fluid conducting hose (see infra).

Referring now particularly to FIGS. 5 and 6, the barrel 540 is providedwith a plurality of windows 542 spaced equally apart around thecircumference thereof. Disposed in each window for radial in and outmovement is a bore wall engageable shoe 544. Each shoe is provided witha plurality of teeth 545 or other means for preventing axial andcircumferential slippage of the shoe when engaged with a bore wall.

Each shoe is sealed to its window byan elastomer (rubber) seal 548,bonded to the window and to the sides and inner periphery of the shoe,the seals 548 merging to form a continuous sleeve around the tube 532.The seals normally hold the shoes as shown in the unset or retractedposition and have sufficient resilience to allow the shoe to beprojected radially outwardly into bore wall engaging or set positionwhen fluid pressure in chamber 544 exceeds that outside the forceapplicator. Upon equalization of such pressures, the resistence of theseals retracts the shoes to the disengaged or retracted position shown.

The sides 549 of the barrel 540 are flattened to provide fluid passagemeans between the barrel and the wall of the earth bore in which theapparatus is used. Further details of the operation of such wall anchormeans are set forth in the aforementioned Kellner and Bachman et al.patents.

Referring now to FIGS. 7-9 there are shown the details of the piston andcylinder means 83 shown schematically in FIG. 1. Cylinder 77 is screwconnected at 550 to coupling 538, by which means it is connected tobarrel 540 and spline tube 69 (FIG. 4). The outer end of cylinder 77 isconnected by threaded coupling 552 to guard cup 554.

Reverting for a moment back to FIG. 3, as previously mentioned the outerend 525 of guard cup 524 cooperates with the inner end 62 of sub 61 toprovide stop means limiting relative axial travel of the mandrel andspline tube 69. Since the spline tube is connected to anchor barrel 540,this stop means also limits relative axial travel of the mandrel and theanchor barrel in one direction. Relative axial travel of the mandrel andthe anchor barrel 540 in the opposite direction is limited by stop meanscomprising guard cup 554 and barrel head 556 (FIG. 10) of the mandrelanchor and guide means 85. The end 558 of the guard cup 554 engages end560 of barrel head 556 to limit such motion. Within the limits ofrelative axial motion of the mandrel and cylinder anchor barrel justdescribed, mandrel port 541 (FIG. 4) is always in communication withchamber 543.

Referring once more to the piston and cylinder means 83 shown-in FIGS.7-9, pipe 532 of the piston rod section 79 of the mandrel of the forceapplicator extends axially through cylinder 77 and is axially slidablysealed thereto by seals S34 and 562, respectively bonded to seal rings536 and 564. The latter are press or shrink fitted in couplings 538 and552 and together with the seals carried thereby provide cylinder heads.In the space between the cylinder heads travels piston 81 which issecured to pipe 532 Part of the drawing'is broken off between cylinderheads 536 and 564; the length of cylinder 77 and pipe 532 actually willbe about the same as the length of the spline tube and the mandrelsection therewithin, and the same as the length of the cylinder anchorbarrel and the mandrel section therewithin, so as to provide equalstrokefor the spline means and the cylinder anchor means and the piston andcylinder means. The stop means previously described which limit relativeaxial travel of the mandrel and cylinder anchor barrel'also prevent thepiston from contacting the cylinder heads and prevents the spline sleeve67 from striking the barrel 540 (FIG. 4) and the barrel head 526 (FIG.3).

Piston 81 comprises annular body 566 which is secured to the tube 532 bycollet clamp 568, the latter being activated by compression ring 570.Ring 570 is screwed into body 566. Ring 566 is sealed to tube 532 byrubber O-bo'dy 572. The exterior of piston body 566 is bonded to rubberseal 574. This-construction is described in greater detail in theaforementioned contemporaneous Kellner application to which referencemay be made if need be.

Pressure fluid conduits 605, 607 are connected to mandrel ports 609, 611whereby pressure fluid can be supplied to and released from the spaces613, 615 at the inner and outer ends of the piston and cylinder means onthe opposite sides of the piston. The ends 617', 619 of the piston body566 and ring 570 are spaced radially outwardly from the mandrel so thatports 609, 611 can be placed thereunder without being blocked; thisallows the ports to be placed that much closer together, to increase theeffective stroke of the piston and cylinder means. Wrench sockets 618,620 are provided in the ends 617, 619 to facilitate screwing ring 570into body 566.

Pipe 532 of the piston rod section of the mandrel extends outwardly fromguard cup 554 to the hose connection, mandrel anchor and guide means 85shown in detail in FIGS. 10-16.

Referring particularly to FIG. 10, pipe 532 is welded at its outer endto manifold 630. Mandrel anchor barrel 632 is screwed at its outer endto manifold 630 in fluid tight'relationship and is screwed at its innerend to barrel head 556, also in fluid tight relationship. Head 556 issealed to pipe 532 by rubber O-ring 634. There is thereby definedbetween barrel 632, pipe 532, seal 634, and manifold 630 a chamber 636.

There are a plurality of windows 638 in barrel 632 equally spaced apartcircumferentially around the barrel. Within each window is disposed abore wall engageable shoe 640. Each shoe is sealed to its window by anelastomer (rubber) seal 642 bonded to the window and to the sides andinner periphery of the shoe, the seals being connected to their radiallyinnermost portions provide a continuous sleeve around pipe 532.Application of fluid pressure inside chamber 636 exceeding that outsidethe force applicator causes the shoes to be moved outwardly into borewall engaging or set position; equalization of the pressures causes theelastic seals to retract the shoes back to the position shown. Even inretracted position the shoes are sufficiently close to bore wallengagement to serve as centralizing or guiding means for the mandrel ofthe force applicator. During drilling the mandrel is guided by the sealsof the barrel heads of the cylinder anchor barrel and the seals of thecylinder heads of the piston and cylinder means, and by the pistonmoving in the cylinder of the piston and cylinder means, and by the ribs519 of the spline sleeve moving in the channels 525 of the spline tube,and by the shoes of the mandrel anchor barrel moving in the bore hole. t

The flat sides 642 (FIG. 12) of the body 632 of the mandrel anchorprovide fluid passages between such body and the bore wall. The shoes640 are provided with teeth 644 which provide means to prevent axial andcircumferential slippage between the mandrel anchor'barrel and bore wallwhen the shoes are in theextended or set position.

For supplying pressure fluid to the pipe 532 connecting to the Dyna-Drilor other drilling machine and to supply pressure fluid to the conduits605, 607 leading to the inner and outer spaces of the piston andcylinder means, and to chamber 636 of the mandrel anchor means and toconduit 546 leading to the cylinder anchor means, the manifold 630isprovided with five fluid passages 700, 702, 704, 706 and 708 as bestshown in FIGS. 15 and 16. Passage 700 is in direct communication withthe interior of tube 532 via counterbore 710, as shown in FIG. 10.

Referring to FIGS. 10 and 15, passage 702-communicates via radialpassage 712 with axially extending passage 714 that connects to conduit605 which is received in a counterbore at the end of passage 714.Similarly, passage 704 communicates via transverse passage 716 withaxially extending passage 718 which connects to conduit 607 which isreceived in a counterbore at the end of passage 718.

Passage 706 communicates via radial passage 720 (FIG. 14) with axiallyextending passage 722 which is connected to conduit 546, the latterbeing received in a counterbore in passage 722.

Passage 708 (FIGS. 10 and 14-l6) connects directly with chamber 636 ofthe mandrel anchor means.

Referring now to FIGS. 11 and 16, the outer ends of manifold passages700, 702, 704, 706, 708 are connected to hose connection coupling means724, 726, 728, 730, 732. The apparatus is thus adapted for operation byconnection to five separate flexible, pressurefluid hoses extendingthrough the earth bore to the outer end of the bore. To eliminate thepossibility of tangling the hoses and to facilitate reeling and winchingat the bore face, it is preferred to bundle them together to form asingle line 87 as shown in FIGS. 1 and 17. It will be understood thatthis can be accomplished simply by helically wrapping a tape around thefive hoses in order to hold them together in a single bundle, or aprefabricated multipassage hose can be used.

Referring now to FIG. 17, there is shown the in-hole apparatus as it isbeing launched into the earth bore through guide funnel 91 from suitableout-of-hole app'aratus. The out-of-hole apparatus includes a fourwheeled trailer cart 798 on which is rotatably mounted reel 800 on whichthe hose line 87 is wound bysuitable means, e.g. with level windmeans asdisclosed in the aforesaid contemporaneously executed Kellnerapplication. The line 87 passes over suitable guide pulleys (not shown)to power winch 802. After several turns around winch 802 sufficient toestablish the frictional engagement needed for pulling on the hose linewith the desired force the hose line 87 connects to the hose couplingend of the force applicator 64.

Whe not in use the force applicator is carried in a storage and launchtube 804 affixed to the side of the cart. When it is desired to use theapparatus drilling machine 57 is placed inside an extension tube 806.The drilling machine is then connected to the force applicator 64 by sub61 and the extension tube 806 is connected to storage and launch tube804 by coupling 808. The cart 798 is positioned to place the end ofextension tube 806 against guide funnel 91. With the cart 798 heldstationary the force applicator can then be used to load the drillingmachine to start the earth bore, purchase being obtained from the tubes804 and 806 as the force applicator moves therethrough into the earthbore. a

' The end of hose line 87 is connected through suitable swivel means,not shown, which may be like that disclosed in the aforesaidcontemporaneously executed Kellner application, to pressure fluidsupplyand control means carried by cart 798. For example, water emerging fromthe drill bit 53 and returning to receiving tank 810 through the earthbore 53 can be pumped out via pipe 812 by an electric motor driven pump(see FIG. 19) mounted in console 814. The water is then delivered to theflow passage of hose line 87 that delivers fluid to the drilling machine57. The details of this could be the same as inthe. aforementionedcontemporaneous Kellner application. Also mounted in console 814 is anair motor driven pump for hydraulic fluid together with suitablecontrols for supplying the hydraulic fluid to the two anchor means andto the piston and cylinder means of the force applicator. The details ofsuch control and hydraulic fluid supply means are shown in FIG. 18. Thesymbols used in FIG. 18 are those of the United States of AmericaStandards Institute, e.g. as illustrated and disclosed in the 1968/69Fluid Power Handbook & Directory pages A/36-A/46.

Referring now to FIG. 18 there is shown a piston pump 900 driven by airmotor 902 from a suitable source-of compressed air (not shown). The pumpintake is connected to hydraulic fluid (oil, or preferably water becauseof its lower viscosity) tank 904 by line 906 through filter 908 anddischarges through line 910 to accumulator 912.

Line 910 also is connected through line 914 and variable choke 916, line917 and manual dump valve 918 to branch lines 920, 922, with pressuregage 924 and relief valve 926 branching off from line 9.17.

Branch lines 920, 922'are connected to one-way pressure'control means928, 930, each comprising a check valve 932, 934 in parallel with aspring loaded valve 936, 938. Valve 936 is normally open but closeschokes down to prevent downstream pressure from increasing above a setpressure. Valve 938 is normally closed and does not open until upstreampressure reaches a certain value, whereupon downstream and upstreampressure become equal. A pressure gage 940 is connected to pressurecontrol means 928 downstream from valve 936.

Pressure control means 928 is connected throug line 942 to air actuated,spring centered, three position valve 944 and manually reversing valve946 to mandrel anchor means 73, or, if the reversing valve 946 is movedto the opposite position from that shown, to cylinder anchor means 85.Tank 904 is connected through air operated three position valve 944 andreversing valve 946 to cylinder anchor means 85, or, if the reversingvalve 946 is moved to the opposite position from that shown, to themandrel anchor means 73.

if three position valve 944 is moved to the right from the positionshown, in its mid position it will connect both anchor means 73, 85 tohydraulic line 942 and block off the connection thereof to tank 904.Further movement of valve 944 to the right will reverse the connectionof the anchor means with respect to tank 904 and hydraulic line 942 fromthe position shown in the drawing. Valve 944 is moved from left to rightand back again by air pressure through lines 950,952 which are connectedthrough one way time delay (e.g. sec.) means 954, 956 and manualreversing valve 958 to lines 960, 962. Line 960 is connected to a source(not shown) of air under pressure. Line 962 is connected to atmosphere.

The one-way time delay means 954, 956 comprise adjustable throttlevalves (needle valves) 953, 955 in series with air chambers 957, 959,the valves being bypassed by check valves'951, 96], whereby fluid canflow freely without time delay in the direction the check valves openbut must fill the chambers 957, 959 through chokes 953, 955 beforebuilding up full pressure downstream when flowing in the otherdirection.

Air is also conducted from time delay means 954, 956 to air operatedhydraulic reversing valve 964. Valve 964 controls flow through line 963to tank 964 and from line 966 leading to time delay means 930. Lines 966and 963 connect through valve 964 to hydraulic lines 968, 970, which inturn connect through one-way pressure regulator means 972, 974 to outerand inner spaces 615, 613 on opposite sides of piston 81 carried on tube532 inside cylinder 77. The one-way pressure regulator means 972, 974comprise pressure relief valves 971, 973, respectively in parallel withcheck valves 975, 977. Pressure gages 976, 978 con-. nected to spaces615, 613 indicate which space is pressurized.

The hydraulic fluid supply and control means provided by the apparatusshown in FIG. 18 is in the deactivated position due to dump valve 918being in the dump position. In that position both lines 942 and 966 areconnected to discharge to tank 904 through check valves 932 and 934 anddump valve 918. This means that whichever anchor means 73, 85 isconnected to line 942 through valves 944 and 946 is dumped to tank 904;likewise, whichever one of spaces 615, 613 of the pistonand cylindermeans 83 is connected to line 966 through valve 964 is also dumped totank 904.

In addition, line 917 from the accumulator. is. also dumped to tank 904through valve 918. The one of the anchor means not connected to line 942is also dumped to tank 904, through line 990, and the one of the spaces615, 613 of the piston and cylinder means 81 that is not connected toline 966 is also dumped to tank 904, through line 963. Therefore, withthis position of dump valve 918, the positions of cycle valve 958 andreverse valve 946 are immaterial, for the apparatus is fullydeactivated.

To operate the apparatus .the dump valve 918 is moved to the right. Thisconnects hydraulic line 917 to lines 920, 922. With both the cycle valve958 and the reverse valve 946 in the drill positions as shown, hydraulicfluid is supplied to cylinder anchor means 73 to set it in bore wallengaging position. As soon as the pressure builds up, valve 938 opensand hydraulic fluid is applied to the outer space'613 of the piston andcylinder means 81 to apply force to the drilling machine.

When the stroke limit of the force applicator is reached, the operatorwillbe apprised of that fact by a fall in pressure at the gate 992 (FIG.19) on the outlet of electric motor driven pump 994 that picks up waterfrom pipe 812 and delivers it to the drilling machine. Such a falloccurs because the drilling machine is no longer loaded.

The operator then moves cycle valve 958 to the left or reset position.This connects time delaymeans 954 to air vent 962 and allows thecentering springs on valve 944 to move it to the right to centeredposition. At this time both the cylinder and mandrel anchor means 73, 85are set. After the preset time delay, time delay means 956 connects airpressure line 960 to lines 998 and 950 to move valve 964 to the left andvalve 944 to the right. Cylinder anchor means 73 is thereby dumped andhydraulic line 966 is thereby connected to the inner space 613 of thepiston and cylinder means to move the cylinder 77 to a new positionfarther inward in the earth bore. This will only take a minute, moreorless, depending on the capacity of the hydraulic pump 900 and thevolume of cylinder 77. The operator will be apprised of the fact thatthe stroke limit has been reached by a rise in pressure at gauge 978.

To resume drilling the operator moves cycle valve 958 to the right. Airline 950 is thereby dumped to atmospheric vent 962, allowing the springsof valve 944 to move it to its center position. Both the cylinder andpiston anchor means 73, 85 are thereby connected to hydraulic line 942,setting the cylinder anchor means in addition to the already set mandrelanchor means 85. After the predetermined time delay of time delay means954, air pressure line 960 will be connected to lines 952 and 999,moving valves 944 to the left and valve 964 to the right. This willcause mandrel anchor means 85 to be connected to tank'904, retractingan-' chor means 85. As soon as pressure in the hydraulic line 922 issufficient to open valve 938, hydraulic pressure fluid will be connectedto outer space 615 of the piston and cylinder means 83, and the drillingmachine will once more be loaded. The foregoing sequence can be repeatedas the apparatus alternately reaches the end of the drilling stroke andthen is reset.

If it is desired to remove the apparatus from the earth bore, theoperator has two options. He can move dump valve 918 to the left,deactivating the piston and cylinder means and both anchor means. Thewinch 802 can then be operated to pull the hose bundle 87 and the forceapplicator 64 and the drilling machine 57 out of the earth bore.

Alternatively the operator can move the reverse valve 946 to the left orretract position. This will cause the mandrel anchor means 85 to be set,rather than the cylinder anchor means 73, when the cycle valve 958 is inthe drill position. Therefore, when hydraulic fluid pressure is appliedto the outer space 615 of the piston and cylinder means 83, the cylinder77 is moved outwardly. When it reaches its stroke limit as indicated bya rise in pressure at gauge 976, the cycle valve is moved to the left tothe reset position. This causes mandrel anchor means 85 to be retractedand cylinder anchor means 73 to be set, while hydraulic fluid pressureis applied to inner space 613 of the piston and cylinder means 83. Thepiston 81 of the piston and cylinder means is thereby moved outwardly toretract the apparatus from the earth bore. When its stroke limit isreached as indicated by a rise in pressure at gauge 978 the cycle valveis returned to the right or drill position.

1 By repeating the foregoing sequence, moving the cycle valve 958 backand forth as the stroke limits are reached, the apparatus is retractedfrom the earth bore under its own power.

During withdrawal of the apparatus from the earth bore the water orother pressure fluid supply to the drilling machine can be maintained.Alternatively, it can be continued at a reduced pressure by openingbypass throttle valve 1000 (FIG. 19) to a greater or lesser degree. Ifdesired, the pressure fluid to the drilling machine can be shut offaltogether by shutting down pump 994. This is accomplished by openingswitch 1002 in the electric line connecting electric motor 1004 to asuitable source of electric power (not shown).

The apparatus is provided with a number of protective devices. Pressurerelief valve 1006 prevents excessive water pressure from being suppliedto the drilling machine. Pressure regulating valves 972, 974 limit thepressure applied to the piston and cylinder means 83. Pressureregulating valve 936 limits the pressure applied to the two anchormeans. Pressure relief valve 926 limits the pressure applied to theaccumulator 912 and to the entire hydraulic system.

The pressure fluid supply and control system of FIG. 18 can beautomated, if desired, in the same manner as described in detail in theaforementioned contemporaneously executed Kellner application, e.g. byincluding an out-of-hole pilot piston and cylinder means in series withone of the lines 968, 970, and causing the motion of the pilot pistonrod to actuate cycle valve 958 as the piston and cylinder means reachesthe ends of its stroke.

While a preferred embodiment of the invention has I been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit of the invention.

That being claimed is:

1. Apparatus useful in earth boring comprising a wheeled cart, reelmeans carried by the cart, multipassage hose means wound on the reel, astorage and launch tube mounted on the cart, a bore wall engageableforce applicator adapted to be supported in said tube and projectabletherefrom, said hose means being including a piston connected to themandrel and a cylinder in which the piston is slidable, anti-rotationmeans preventing relative rotation of the mandrel and cylinder, firsthydraulically actuated anchor means connected to said cylinder at theend thereof nearest said drilling machine, second hydraulically actuatedanchor means connected to said mandrel on the opposite side of saidpiston and cylinder means from said first anchor means adjacent said oneend of the .force applicator to which said hose is connected, and pressure fluid supply and control means connected to said hose means forseparately supplying fluid to said drilling machine, each of said anchormeans, and to the piston and cylinder means on opposite sides of saidpiston, said supply and control means including two sources of pressurefluid one of which is connected to a passage of said hose means thatcommunicates with said drilling machine and the other which is carriedby said cart and is in communication with separate passages in said hosemeans communicating with said two anchor means and with said piston andcylinder means on opposite sides of the'piston thereof, said control andsupply means further including on said cart two separate meansregulating the pressure of fluid supplied to said piston and cylindermeans on opposite sides of the piston, a third means for regulating thepressure of fluid supplied to said anchor means, and two separate valveunits, one unit connecting a selected one of said anchor means with saidsecond source while disconnecting the other therefrom and the other unitconnecting said second source to said piston and cylinder means on oneside of the piston while disconnecting from said second source thepiston and cylinder means at the other side of the piston, and gagemeans indicating the pressure supplied to said anchor means and to saidpiston and cylinder means on opposite sides of the piston thereof.

end of said hose means being connected to said force applicator.

3. Apparatus according to claim 2 wherein said support includes a cartand wheel means supporting said cart for movement in a horizontaldirection, said storage and launch tube is mounted on said cart to be ina horizontal position when said cart is supported by said wheel meansfor such horizontal movement, said reel means is mounted for rotationabout an axis parallel to the axis of said tube, said apparatus furtherincluding power winch means mounted for rotation about an axis that isvertical when said cart is supported by said wheel means as aforesaid,said hose means passing around said winch means between said reel meansand said force applicator, the edge of the inner periphery of saidstorage and launch tube nearest said winch means being tangent to theouter periphery of said winch means.

4. Apparatus according to claim 2, said force applicator including atubular mandrel providing fluid passage means to convey drilling fluidand providing means to apply axial force to a drilling machine whenconnected to the mandrel, two releasable anchor means each including abarrel disposed around the mandrel and sealed thereto at axially spacedpositions defining a chamber between the barrel and mandrel, bore wallengageable means mounted in the barrel for motion outwardly relative tothe mandrel axis and back toward it in response to the pressuredifferential between inside said chamber and outside said forceapplicator, and conduit means extending through the mandrel forsupplying pressure fluid to said chamber,

piston and cylinder means for exerting an axial force on said mandrelincluding a piston connected to said mandrel, a cylinder disposed aroundsaid piston and axially slidable relative thereto, and separate conduitmeans extending through said mandrel for supplying 'pressure fluid tosaid cylinder on opposite sides of said piston,

the barrel of one of said, anchor means being fixedly connected to saidmandrel,

the barrel of the other of said anchor means being fixedly connected tosaid cylinder, and

means preventing relative rotation of said cylinder and said mandrel,

said bore wall engageable means being engageable with the innerperiphery of said storage and launch tube when moved outwardly undersaid pressure differential.

5. Apparatus according to claim 4 wherein said anchor means are disposedon opposite sides of said piston and cylinder means, said one anchormeans fixedly connected to said mandrel being disposed adjacent the endof said force applicator to which is connected said hose means.

6. Apparatus according to claim 5, said hose means providing fiveparallel fluid paths, said hose means being connected to said forceapplicator by a manifold having five fluid passages therethrough, saidfive fluid passages being connected respectively to said two anchormeans and to two opposite sides of said piston and cylinder means and tosaid fluid passage means to convey drilling fluid, said manifold alsoproviding the means by which the barrel of said one anchor means isconnected to said mandrel.

7. Apparatus useful in earth boring, said apparatus comprising a forceapplicator includng a tubular mandrel having means at one end thereoffor makingconnection at least indirectly with a drilling machine, saidone end constituting the inner end of the mandrel and the opposite endof the mandrel constituting the outer end of the mandrel,

said mandrel providing means to apply force to such drilling machinewhen connected thereto,

bore wall engaging means concentric piston and cylinder means forapplying axial force to said mandrel incluidng a piston connected tosaid mandrel and a cylinder within which said piston is axially slidablydisposed,

cylinder anchor means for releasably anchoring said cylinder to the wallof an earth bore,

spline means for preventing relative rotation of said mandrel andcylinder while allowing relative axial motion thereof, and

mandrel anchor means for releasably anchoring said mandrel to the wallof an earth bore,

each of said anchor means including bore wall engageable means extendingradially outwardly beyond the outer periphery of said mandrel even 'whensaid anchor means is released from bore wall engaging position, wherebysaid anchor means serve also as guide means for said mandrel,

said releasable anchor means being disposed at opposite ends of saidbarrel and cylinder means.

8. Apparatus according to claim 7,

said cylinder anchor means being connected to said cylinderat the endthereof nearest said inner end of the mandrel,

said mandrel anchor means being connected to said mandrel at the side ofsaid piston and cylinder means nearest the outer end of said mandrel. 9.Apparatus according to claim 8 wherein said mandrel is tubular providingfluid passage means to supply pressure fluid from the outer end of themandrel to a drillingmachine connected to said inner end of saidmandrel,

each of said anchor means including return fluid passage means toconduct past said anchor means exteriorly of said mandrel pressure fluidreturning from such drilling machine between the force applicator and anearth bore therearound,

said piston and cylindermeans lying between said anchor means andspacing them apart at all times, thereby assuring that said return fluidpassage means in one anchor means is not blocked by the bore wallengaging means of the other anchor means when said mandrel movesrelative to said cylinder.

10. Apparatus according to claim 9,

each of said anchor means including a barrel around the mandrel, meanssealing between the barrel and mandrel at positions spaced apart axaillyof the mandrel forming between said seals and said barrel and saidmandrel a chamber,

. each bore wall engageable means of each of said anchor meanscomprising a shoe mounted in a window in the barrel of said anchor meansand projectable radially outwardly by pressure fluid within the chamberof said anchor means,

said force applicator further including a manifold connected to theouter end of said mandrel anchor means providing means to connect theforce applicator to means for separately supplying pressure fluid toeach of said anchor means, the piston and cylinder means on both sidesof said piston, and to a drilling machine connected to the inner end ofsaid force applicator.

11. Apparatus according to claim 10,

said mandrel being also connected to the outer end of the barrel of saidmandrel anchor means and providing the outermost of one of said sealsbetween said mandrel and said mandrel anchor means.

12. Apparatus according to claim 11,

said manifold including a first fluid passage connected at its inner endwith the outer end of said mandrel in communication with said fluidpassage means to supply pressure fluid to a drilling machine connectedto said one end of the mandrel,

said manifold further including a second fluid passage directlyconnected at its inner end with the chamber of said mandrel anchormeans,

said manifold further including third, fourth and fifth fluid passagesconnected to conduits in said mandrel leading to said cylinder anchormeans and to said piston and cylinder means on opposite sides of saidpiston.

13. Apparatus useful in earth boring, said apparatus comprising a forceapplicator including a mandrel having means at one end thereof formaking connection at least indirectly with a drilling machine, said oneend constituting the inner end of the mandrel and the opposite end ofthe mandrel constituting the outer end of the mandrel, v

said mandrel providing means to apply force to such drilling machinewhen connected thereto,

piston and cylinder means for applying axial force to said mandrelincluding a piston connected to said mandrel and a cylinder within whichsaid piston is axially slidably disposed,

cylinder anchor means for releasably anchoring said cylinder to the wallof an earth bore,

spline means for preventing relative rotation of said mandrel andcylinder while allowing'relative axial motion thereof, and

mandrel anchor means for releasably anchoring said mandrel to the wallof an earth bore,

said mandrel being tubular providing fluid passage means to supplypressure fluid from the outer end of the mandrel to a drilling machineconnected to said inner end of the mandrel,

each of said anchor means incluidng a barrel around the mandrel, meanssealing between the barrel and mandrel at positions spaced apart axiallyof the mandrel forming between said seals and said barrel and saidmandrel a chamber,

each of said anchor means further including bore wall engageable meanscomprising a shoe mounted in a window in the barrel of said anchor meansand projectable radially outwardly by pressure fluid with the chamberofsaid anchor means,

said force applicator further including multipassage means forseparately supplying pressure fluid to each of said anchor means and tothe piston and cylinder means at each side of said piston,

flexible hose means connected at one end to the outer end of said forceapplicator and including first, second, third, fourth, and fifthchannels, the first of said five channels communicating with said fluidpassage means to supply pressure fluid to a drilling machine connectedto theforce applicator, and said second, third, fourth and fifthchannels communicating respectively via said multipassage means withsaid two anchor means and the piston and cylinder means on oppositesides of the piston thereof,

pressure fluid supply and control means connected to the other end ofsaid hose means for selectively supplying pressure fluid to saidchannels as desired,

said pressure fluid supply and control means including a first source ofpressure fluid for supplying drilling fluid to said' first channel and asecond is source of pressure fluid for supplying hydraulic fluid to theremainder of said channels,

said pressure fluid supply and control means further including 1 a firstvalve unit selectively to connect one of said second and third channelsto said second source of pressure fluid and disconnect the othertherefrom and a second valve unit selectively to connect one of saidfourth and fifth channels to said second source of pressure fluid anddisconnect the other therefrom.

14. Apparatus according to claim 13, said pressure fluid supply andcontrol means including means independently to regulate the pressure offluid supplied to each of said fourth and fifth channels.

15. Apparatus according to claim 14 wherein said first valve is a threeposition valve in a center position of which both of said second andthird channels are connected to said second source of 7 pressure fluidthereby to insure that shifting the condition of the apparatus from thatin which an anchor means is set to that in which the other anchor meansis set, one of said anchor means is always set.

16. Apparatus useful in earth boring including a force applicatorcomprising a tubular mandrel, a cylinder around the outside of themandrel, a piston affixed to the mandrel slidable in the cylinder, twobarrels around the mandrel, one barrel being connected at one end to oneend of the cylinder, the other barrel being connected at one end to themandrel at the opposite end of said cylinder from said first barrel,spline means connecting said mandrel and cylinder, hydraulicallyactuatable shoes carried by each barrel, first conduit means inside saidmandrel extending from a port in said mandrel inside said first barrelthrough saidcylinder and second barrel to the end of said mandrel,second conduit means extendng inside said mandrel from said end of themandrel to a port in the mandrel communicating with said cylinder on oneside of said piston, third conduit means extending inside said mandrelto a port in the mandrel communicating with said cylinder 0n the otherside of said piston, the mandrel being otherwise clear of conduitsleaving a passage means therethrough for communication with a drillingmachine when connected to the other end of the mandrel, and passagemeans communicating with the interior of said second barrel.

17. Apparatus according to claim 16 including a manifold connected tothe first said end of the mandrel for connecting multipasage hose meansto the three conduits in the mandrel and said passage means in themandrel and said passage means communicating with the interior of thesecond barrel, said manifold also providing means by which said secondbarrel is connected to the mandrel as aforesaid, and said passage meanscommunicating with the interior of said second barrel being formedinsaid manifold.

18. Apparatus useful in earth boring including a mandrel, a bore aroundthe outside of the mandrel, a manifold which at one end provides meansmechanically connecting one end of the barrel to one end of the mandrel,hydraulically extendable bore wall engaging means carried by the barrel,first fluid passage means through the manifold connecting the spaceinside the barrel outside the mandrel with the other end of themanifold, second fluid passage means through the manifold connecting theinterior of the mandrel with said other end of the manifold, and meansat said other end of the manifold for connecting said fluid passagemeans with a flexible hose bundle.

1. Apparatus useful in earth boring comprising a wheeled cart, reelmeans carried by the cart, multipassage hose means wound on the reel, astorage and launch tube mounted on the cart, a bore wall engageableforce applicator adapted to be supported in said tube and projectabletherefrom, said hose means being connected to one end of saidapplicator, a drilling machine connected to the other end of said forceapplicator, said force applicator including a tubular mandrel providingmeans for conveying operating fluid to said drilling machine,hydraulically actuated piston and cylinder means for applying axialforce to the mandrel and including a piston connected to the mAndrel anda cylinder in which the piston is slidable, anti-rotation meanspreventing relative rotation of the mandrel and cylinder, firsthydraulically actuated anchor means connected to said cylinder at theend thereof nearest said drilling machine, second hydraulically actuatedanchor means connected to said mandrel on the opposite side of saidpiston and cylinder means from said first anchor means adjacent said oneend of the force applicator to which said hose is connected, andpressure fluid supply and control means connected to said hose means forseparately supplying fluid to said drilling machine, each of said anchormeans, and to the piston and cylinder means on opposite sides of saidpiston, said supply and control means including two sources of pressurefluid one of which is connected to a passage of said hose means thatcommunicates with said drilling machine and the other which is carriedby said cart and is in communication with separate passages in said hosemeans communicating with said two anchor means and with said piston andcylinder means on opposite sides of the piston thereof, said control andsupply means further including on said cart two separate meansregulating the pressure of fluid supplied to said piston and cylindermeans on opposite sides of the piston, a third means for regulating thepressure of fluid supplied to said anchor means, and two separate valveunits, one unit connecting a selected one of said anchor means with saidsecond source while disconnecting the other therefrom and the other unitconnecting said second source to said piston and cylinder means on oneside of the piston while disconnecting from said second source thepiston and cylinder means at the other side of the piston, and gagemeans indicating the pressure supplied to said anchor means and to saidpiston and cylinder means on opposite sides of the piston thereof. 2.Apparatus useful in earth boring, said apparatus comprising a support,reel means carried by the support, hose means wound on the reel, astorage and launch tube carried by said support, a bore wall engageableforce applicator disposed in said tube, one end of said hose means beingconnected to said force applicator.
 3. Apparatus according to claim 2wherein said support includes a cart and wheel means supporting saidcart for movement in a horizontal direction, said storage and launchtube is mounted on said cart to be in a horizontal position when saidcart is supported by said wheel means for such horizontal movement, saidreel means is mounted for rotation about an axis parallel to the axis ofsaid tube, said apparatus further including power winch means mountedfor rotation about an axis that is vertical when said cart is supportedby said wheel means as aforesaid, said hose means passing around saidwinch means between said reel means and said force applicator, the edgeof the inner periphery of said storage and launch tube nearest saidwinch means being tangent to the outer periphery of said winch means. 4.Apparatus according to claim 2, said force applicator including atubular mandrel providing fluid passage means to convey drilling fluidand providing means to apply axial force to a drilling machine whenconnected to the mandrel, two releasable anchor means each including abarrel disposed around the mandrel and sealed thereto at axially spacedpositions defining a chamber between the barrel and mandrel, bore wallengageable means mounted in the barrel for motion outwardly relative tothe mandrel axis and back toward it in response to the pressuredifferential between inside said chamber and outside said forceapplicator, and conduit means extending through the mandrel forsupplying pressure fluid to said chamber, piston and cylinder means forexerting an axial force on said mandrel including a piston connected tosaid mandrel, a cylinder disposed around said piston and axiallyslidable relative thereto, and separate conduit means extending throughsaid mandrel for supplyiNg pressure fluid to said cylinder on oppositesides of said piston, the barrel of one of said anchor means beingfixedly connected to said mandrel, the barrel of the other of saidanchor means being fixedly connected to said cylinder, and meanspreventing relative rotation of said cylinder and said mandrel, saidbore wall engageable means being engageable with the inner periphery ofsaid storage and launch tube when moved outwardly under said pressuredifferential.
 5. Apparatus according to claim 4 wherein said anchormeans are disposed on opposite sides of said piston and cylinder means,said one anchor means fixedly connected to said mandrel being disposedadjacent the end of said force applicator to which is connected saidhose means.
 6. Apparatus according to claim 5, said hose means providingfive parallel fluid paths, said hose means being connected to said forceapplicator by a manifold having five fluid passages therethrough, saidfive fluid passages being connected respectively to said two anchormeans and to two opposite sides of said piston and cylinder means and tosaid fluid passage means to convey drilling fluid, said manifold alsoproviding the means by which the barrel of said one anchor means isconnected to said mandrel.
 7. Apparatus useful in earth boring, saidapparatus comprising a force applicator includng a tubular mandrelhaving means at one end thereof for making connection at leastindirectly with a drilling machine, said one end constituting the innerend of the mandrel and the opposite end of the mandrel constituting theouter end of the mandrel, said mandrel providing means to apply force tosuch drilling machine when connected thereto, bore wall engaging meansconcentric piston and cylinder means for applying axial force to saidmandrel incluidng a piston connected to said mandrel and a cylinderwithin which said piston is axially slidably disposed, cylinder anchormeans for releasably anchoring said cylinder to the wall of an earthbore, spline means for preventing relative rotation of said mandrel andcylinder while allowing relative axial motion thereof, and mandrelanchor means for releasably anchoring said mandrel to the wall of anearth bore, each of said anchor means including bore wall engageablemeans extending radially outwardly beyond the outer periphery of saidmandrel even when said anchor means is released from bore wall engagingposition, whereby said anchor means serve also as guide means for saidmandrel, said releasable anchor means being disposed at opposite ends ofsaid barrel and cylinder means.
 8. Apparatus according to claim 7, saidcylinder anchor means being connected to said cylinder at the endthereof nearest said inner end of the mandrel, said mandrel anchor meansbeing connected to said mandrel at the side of said piston and cylindermeans nearest the outer end of said mandrel.
 9. Apparatus according toclaim 8 wherein said mandrel is tubular providing fluid passage means tosupply pressure fluid from the outer end of the mandrel to a drillingmachine connected to said inner end of said mandrel, each of said anchormeans including return fluid passage means to conduct past said anchormeans exteriorly of said mandrel pressure fluid returning from suchdrilling machine between the force applicator and an earth boretherearound, said piston and cylinder means lying between said anchormeans and spacing them apart at all times, thereby assuring that saidreturn fluid passage means in one anchor means is not blocked by thebore wall engaging means of the other anchor means when said mandrelmoves relative to said cylinder.
 10. Apparatus according to claim 9,each of said anchor means including a barrel around the mandrel, meanssealing between the barrel and mandrel at positions spaced apart axaillyof the mandrel forming between said seals and said barrel and saidmandrel a chamber, each bore wall engageable means of each of saidanchor means comprising a shoe mounted in a window in the barrel of saidanchor means and projectable radially outwardly by pressure fluid withinthe chamber of said anchor means, said force applicator furtherincluding a manifold connected to the outer end of said mandrel anchormeans providing means to connect the force applicator to means forseparately supplying pressure fluid to each of said anchor means, thepiston and cylinder means on both sides of said piston, and to adrilling machine connected to the inner end of said force applicator.11. Apparatus according to claim 10, said mandrel being also connectedto the outer end of the barrel of said mandrel anchor means andproviding the outermost of one of said seals between said mandrel andsaid mandrel anchor means.
 12. Apparatus according to claim 11, saidmanifold including a first fluid passage connected at its inner end withthe outer end of said mandrel in communication with said fluid passagemeans to supply pressure fluid to a drilling machine connected to saidone end of the mandrel, said manifold further including a second fluidpassage directly connected at its inner end with the chamber of saidmandrel anchor means, said manifold further including third, fourth andfifth fluid passages connected to conduits in said mandrel leading tosaid cylinder anchor means and to said piston and cylinder means onopposite sides of said piston.
 13. Apparatus useful in earth boring,said apparatus comprising a force applicator including a mandrel havingmeans at one end thereof for making connection at least indirectly witha drilling machine, said one end constituting the inner end of themandrel and the opposite end of the mandrel constituting the outer endof the mandrel, said mandrel providing means to apply force to suchdrilling machine when connected thereto, piston and cylinder means forapplying axial force to said mandrel including a piston connected tosaid mandrel and a cylinder within which said piston is axially slidablydisposed, cylinder anchor means for releasably anchoring said cylinderto the wall of an earth bore, spline means for preventing relativerotation of said mandrel and cylinder while allowing relative axialmotion thereof, and mandrel anchor means for releasably anchoring saidmandrel to the wall of an earth bore, said mandrel being tubularproviding fluid passage means to supply pressure fluid from the outerend of the mandrel to a drilling machine connected to said inner end ofthe mandrel, each of said anchor means incluidng a barrel around themandrel, means sealing between the barrel and mandrel at positionsspaced apart axially of the mandrel forming between said seals and saidbarrel and said mandrel a chamber, each of said anchor means furtherincluding bore wall engageable means comprising a shoe mounted in awindow in the barrel of said anchor means and projectable radiallyoutwardly by pressure fluid with the chamber of said anchor means, saidforce applicator further including multipassage means for separatelysupplying pressure fluid to each of said anchor means and to the pistonand cylinder means at each side of said piston, flexible hose meansconnected at one end to the outer end of said force applicator andincluding first, second, third, fourth, and fifth channels, the first ofsaid five channels communicating with said fluid passage means to supplypressure fluid to a drilling machine connected to the force applicator,and said second, third, fourth and fifth channels communicatingrespectively via said multipassage means with said two anchor means andthe piston and cylinder means on opposite sides of the piston thereof,pressure fluid supply and control means connected to the other end ofsaid hose means for selectively supplying pressure fluid to saidchannels as desired, said pressure fluid supply and control meansincluDing a first source of pressure fluid for supplying drilling fluidto said first channel and a second source of pressure fluid forsupplying hydraulic fluid to the remainder of said channels, saidpressure fluid supply and control means further including a first valveunit selectively to connect one of said second and third channels tosaid second source of pressure fluid and disconnect the other therefromand a second valve unit selectively to connect one of said fourth andfifth channels to said second source of pressure fluid and disconnectthe other therefrom.
 14. Apparatus according to claim 13, said pressurefluid supply and control means including means independently to regulatethe pressure of fluid supplied to each of said fourth and fifthchannels.
 15. Apparatus according to claim 14 wherein said first valveis a three position valve in a center position of which both of saidsecond and third channels are connected to said second source ofpressure fluid thereby to insure that shifting the condition of theapparatus from that in which an anchor means is set to that in which theother anchor means is set, one of said anchor means is always set. 16.Apparatus useful in earth boring including a force applicator comprisinga tubular mandrel, a cylinder around the outside of the mandrel, apiston affixed to the mandrel slidable in the cylinder, two barrelsaround the mandrel, one barrel being connected at one end to one end ofthe cylinder, the other barrel being connected at one end to the mandrelat the opposite end of said cylinder from said first barrel, splinemeans connecting said mandrel and cylinder, hydraulically actuatableshoes carried by each barrel, first conduit means inside said mandrelextending from a port in said mandrel inside said first barrel throughsaid cylinder and second barrel to the end of said mandrel, secondconduit means extendng inside said mandrel from said end of the mandrelto a port in the mandrel communicating with said cylinder on one side ofsaid piston, third conduit means extending inside said mandrel to a portin the mandrel communicating with said cylinder on the other side ofsaid piston, the mandrel being otherwise clear of conduits leaving apassage means therethrough for communication with a drilling machinewhen connected to the other end of the mandrel, and passage meanscommunicating with the interior of said second barrel.
 17. Apparatusaccording to claim 16 including a manifold connected to the first saidend of the mandrel for connecting multipasage hose means to the threeconduits in the mandrel and said passage means in the mandrel and saidpassage means communicating with the interior of the second barrel, saidmanifold also providing means by which said second barrel is connectedto the mandrel as aforesaid, and said passage means communicating withthe interior of said second barrel being formed in said manifold. 18.Apparatus useful in earth boring including a mandrel, a bore around theoutside of the mandrel, a manifold which at one end provides meansmechanically connecting one end of the barrel to one end of the mandrel,hydraulically extendable bore wall engaging means carried by the barrel,first fluid passage means through the manifold connecting the spaceinside the barrel outside the mandrel with the other end of themanifold, second fluid passage means through the manifold connecting theinterior of the mandrel with said other end of the manifold, and meansat said other end of the manifold for connecting said fluid passagemeans with a flexible hose bundle.